The present invention relates to a milling tool for machining of crankshafts and to a crankshaft milling machine suitable for cooperation with the present milling tool.
Crankshaft milling machines for machining the bearing journals of crankshafts are well known to comprise working or drive spindles which hold the milling tool proper. Such milling tools comprise a milling mandrel or arbor as well as the milling discs secured to the arbor with axial spacings between adjacent discs. Generally, the number of milling discs corresponds to the number of the bearing journals to be milled.
The spacing of the cutting teeth of the milling discs from the rotational axis of the spindle determines the precise dimension or spacing of the milled bearing journal. This applies especially for the position of the crankshaft bearing fit journal. In order to maintain the spacing between adjacent milling discs as precise as possible, it is known to insert spacer bushings between the adjacent milling discs.
However, practical experience has shown that the spacing between the adjacent, milled bearing journals may differ from one workpiece to another. Thus, correspondingly larger tolerances must be taken into account when designing these crankshafts. Further, it is necessary to take these tolerances also into account in the construction and in the subsequent grinding operation.